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mist64/perfect6502

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perfect6502, a MOS 6502 CPU emulator that performs a simulation of the original NMOS 6502 netlist

13 mentions on Hacker News by 4 people: 1 story, 12 comments · first 2014-05-29 · latest 2026-10-17

Mentions per year 13 mentions · busiest year 2020 (3)
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  1. …similar to how visual6502.org simulates the CPU (which even in an optimized C simulation like https://github.com/mist64/perfect6502 is still about 30x slower than a real 6502 at 1 MHz). PS: Let's do some simple napkin math: the Antirez…
    comment by flohofwoe · 2026-10-17 · in The Commodore 64 hardware simulator: break chips and pins, see the results
  2. The core of the simulation are these two functions: https://github.com/mist64/perfect6502/blob/09fc542877a843182... As far as I understood it, this basically re-evaluates the state of a 'dirty list' of transistors though all their…
    comment by flohofwoe · 2026-07-25 · in The Visual 6502
  3. …visualization tools (using the visual6502 team's original reverse engineered netlist data, and https://github.com/mist64/perfect6502 as simulation loop): - 6502: https://floooh.github.io/visual6502remix/ - Z80:…
    comment by flohofwoe · 2026-07-24 · in The Visual 6502
  4. …https://github.com/trebonian/visual6502 ...and there's a C port of the netlist simulation code: https://github.com/mist64/perfect6502 One advantage of this approach is that you can inspect internal chip state that isn't visible on the…
    comment by flohofwoe · 2025-03-30 · in 6502 as a Service
  5. …is 'done'. This is a C port of that inner loop [2]. [1] http://visual6502.org/JSSim/index.html [2] https://github.com/mist64/perfect6502/blob/268d16647c6b9cb0c...
    comment by flohofwoe · 2024-08-06 · in I don't know how CPUs work so I simulated one in code (2019)
  6. …(all being based on the netlists from http://www.visual6502.org/ and the simulation code from https://github.com/mist64/perfect6502 - which is the simulation from visual6502.org ported from JS to C).
    comment by flohofwoe · 2024-04-14 · in Getting into way too much detail with the Z80 netlist simulation (2021)
  7. Likely useful: https://github.com/mist64/perfect6502 and http://www.visual6502.org/ . These are transistor-level simulations based on die shots. From these you can derive the cycle times of each instruction with 100% confidence.
    comment by peterkelly · 2024-04-09 · in The 6502 instruction set as a database
  8. ▲ 1
    Perfect6502, an emulator that performs a simulation of the original 6502 netlist
    story by panic · 2021-03-19 · 0 comments
  9. …should remain the same, I used a C port of the visual6502 Javascript code called 'perfect6502'): https://github.com/mist64/perfect6502 ...I heard though that not all 'trap transistors' which should protect the Z80 from reverse engineering…
    comment by flohofwoe · 2020-07-20 · in Z80 Explorer – a Zilog Z80 netlist-level simulator
  10. …the main performance killer) is about 150x slower on a modern CPU (according to the readme here: https://github.com/mist64/perfect6502 )
    comment by flohofwoe · 2020-02-11 · in Visual 6502 in JavaScript
  11. …from visual6502, and a C re-implementation of the transistor-level simulation, called perfect6502 https://github.com/mist64/perfect6502 )
    comment by flohofwoe · 2020-02-10 · in Visual 6502 in JavaScript
  12. …also faster than the original JS implementation, but I haven't measured that. This is done by https://github.com/mist64/perfect6502 , which is a rewrite of the original JS simulation code to C. but there's only at most one CPU half-cycle…
    comment by flohofwoe · 2019-11-09 · in Visual6502 Remix
  13. …quick note: with the visual6502 project ( http://www.visual6502.org/ ), and the c-implementation ( https://github.com/mist64/perfect6502 ), a fun way to test your emulator timing is to run it in parallel with the gate-level simulation, and…
    comment by zellyn · 2014-05-29 · in Emulating a 6502 with cycle-perfect timing